Interpretive Summary: Hormones, like estrogen, are contained in poultry litter and other animal manures. A runoff study was conducted to determine the effect of manure application rate, addition of aluminum sulfate and multiple storms on estrogen runoff. Manure application rate had a significant effect on estrogen runoff, with higher rates causing more runoff. Aluminum sulfate (alum) applications to poultry litter significantly reduced the amount of estrogen in runoff. The highest concentrations of estrogen were observed from the first storm after litter application.

Technical Abstract:
Environmental loading of hormones contained in poultry litter may cause or contribute to disruptions in the health and reproduction of animals. A runoff study was conducted to evaluate the hypothesis that poultry litter applied to pasture contributes to runoff of the estrogen hormone 17beta-estradiol. The objectives were to determine the effects of (I) rate of litter application, (ii) amending litter with alum [aluminum sulfate (Al2(SO4)3.14H20)], and (iii) multiple storms on runoff concentrations and losses of 17beta-estradiol from poultry litter applied to fescue (Festuca arundinacea Schreber) plots. Normal litter and litter treated in production houses with 1.2 kg alum m**-2 were applied to four replicated plots 1.52 m wide by 3.05 m long on Captina silt loam at 1.76, 3.52, 5.28, and 7.05 Mg ha**-1. Simulated rain was applied immediately thereafter and 7 d later at 50 mm h**-1. Runoff samples were collected at 5 min. intervals for 30 min. beginning 2.5 min. after runoff began, and a single flow-weighted composite was obtained from the six discrete samples. The 17 beta-estradiol content of the composites was determined by enzyme linked immunoassay. First-storm runoff concentrations and mass losses increased with application rate and were 1.28ug l**-1 and 198.8 mg ha**-1 from the highest application rate of normal litter. Amending the litter with alum reduced mean 17beta-estradiol concentrations by 42% and losses by 46% in first-storm runoff. Overall, second-storm runoff concentrations and losses were 66 and 69% less than from the first storm. This research indicates that amending poultry litter with alum can significantly reduce hormone transport in runoff.